Reason: the DMK's official demand is for a CBI probe into her death.   Whichever way one looks at it, the inquiry will have to begin with V K Sasikala, who spent 75 days with Jayalalithaa during her hospitalisation between September and December last year.   

But the DMK is not too happy at involving Sasikala, and there is a political reason for it. She belongs to the Thevar community which the DMK doesn't want to antagonise. Hence its insistence on a CBI probe and the decision to boycott this inquiry commission.